The overall objective of the study is to determine whether self-rated, perceived immune fitness (using questionnaire) is associated with biological assessment of immune fitness (immune signatures in the blood).

Inclusion Criteria:

1. Ability to understand and sign the informed consent
2. Healthy adult men and/or women, 35-65 years old
3. BMI >18 and <30 kg/m2

Exclusion Criteria:

1. Volunteer who cannot be expected to comply with the protocol
2. Individuals with self-reported chronic disease; or who have any clinical condition which the investigator deems relevant for exclusion from the study,
3. Individuals with an impaired immune system that may confound immune response testing; i.e. any condition that impairs participant immune response through either the condition itself or through the treatment of the condition,
4. Family or hierarchical relationships with Clinical Innovation Lab at Nestlé Research, Lausanne, Switzerland

Healthy adults